Savings bonds are sold by governments to encourage their citizens to save rather than spend some of their income, as well as to lend those savings to the government. The savings bonds are similar to ordinary corporate or government bonds, other than some characteristics designed to attract non-professional investors: small minimum investment requirement, special tax regulations, availability from a variety of locations, or low maximum level to discourage institutional investors.
Periods of greatest savings bond sales have been, through history, associated with wartime economies. Two ends are served by such wartime activity: (1) drawing income off into savings and away from day-to-day spending, thusly having too much money and too few goods, thereby driving prices upward; and (2) providing the government with money to pay for the war.